Air ionizer for air purification

ABSTRACT

A Static Electrostatic Generator (SEG) is disclosed which produces static charges at high voltage and low current. The SEG is capable of generating positive or negative charges on a metal sphere by reversing the polarity of a DC source. The conversion efficiency of the system is about 47% and its design is simple, lightweight, and easy to manufacture. The SEG is a static device and no mechanical movement is required to produce charges. Also, the design is easily scalable.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of U.S. application Ser. No.16/364,558, now allowed, having a filing date of Mar. 26, 2019.

STATEMENT OF ACKNOWLEDGMENT

The support provided by the Deanship of Research (DSR) at King FahdUniversity of Petroleum and Minerals (KFUPM) for funding this workthrough Project No. RG171009.

BACKGROUND Technical Field

The present disclosure is directed to a static electrostatic generator(SEG), especially for high voltage, low power applications.Electrostatic charges accumulate on the surface of a metal sphere. TheSEG is a static device and no mechanical movement is required to producecharges.

Description of Related Art

The “background” description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description which may nototherwise qualify as prior art at the time of filing, are neitherexpressly or impliedly admitted as prior art against the presentinvention.

In the early 1900s, physics researchers expressed a need for a highvoltage DC source, in millions of volts, with low current to accelerateelectrons and ions to investigate internal atom structure. However, withthe available equipment at that time, a costly, huge and well-insulatedtransformer and a high voltage rectifier was needed to provide high DCvoltage for a particle accelerator. (See R. L. Fortescue and P. D. Hall,“The high-voltage electrostatic generator at the atomic energy researchestablishment,” Proceedings of the IEEE—Part I: General, Vol. 96, No.98, pp. 77-85, March 1949; J. F. Smee, “A 700-kv direct-currentelectrostatic generator,” Journal of the Institution of ElectricalEngineers—Part I: General, Vol. 91, No. 47, pp. 422-431, November 1944;and F. H. Merrill, “The Van de Graaff electrostatic generator,”Students' Quarterly Journal, Vol. 9, No. 35, pp. 124-127, March 1939,each incorporated herein by reference in their entirety). Van de Graaffet al. presented a simple and economical solution to produce a high DCvoltage source using a low current source. (See Van de Graaff et al.“The electrostatic production of high voltage for nuclearinvestigations,” Physical Review, Vol. 43, Issue 3, pp. 149-157,02/1933, incorporated herein by reference in its entirety).

Since the inception of the electrostatic generator and its impact onnuclear physics research, it has received much attention and hasfrequently been the object of research.

In the renewable energy sector, electrostatic generation plays animportant role. With increasing energy demands worldwide and effects toearth's ecosystem, such as global warming and pollution, caused bytraditional energy sources, such as oil, coal and nuclear, the need forthe renewable energy sources has increased. The increasing demands ofrenewable energy sources, capital cost reduction, and efficientrenewable energy systems have motivated researchers to investigate waysto improve renewable energy to make it a more viable economic option. Avariable capacitor, a type of electrostatic generator, as a power sourcefor space applications using electrets was studied. (See R. E. Matthew,“The use of electrets in electrostatic generators for space,” ElectricalEngineering, Vol. 81, No. 11, pp. 850-854, November 1962, incorporatedherein by reference in its entirety). More recently, electrostatic powergeneration for wind turbines shows promising results for power gridgeneration. An offshore wind farm utilizing an HVDC generator totransmit power efficiently may eliminate the need for an AC to DCconverter since the electricity generated is DC. (See R. O'Donnell, N.Schofield, A. C. Smith, and J. Cullen, “Design concepts for high-voltagevariable-capacitance dc generators,” IEEE Transactions on IndustryApplications, Vol. 45, No. 5, pp. 1778-1784, September 2009,incorporated herein by reference in its entirety). An electrostatic windconverter (EWICON) was developed to replace traditional wind generators.EWICON generates electrical power by forcing charges to move in adirection opposite to the electric field by using the wind to increasethe energy of the system. (See D. Djairam, P. H. F. Morshuis, and J. J.Smit, “A novel method of wind energy generation—the electrostatic windenergy converter,” IEEE Electrical Insulation Magazine, Vol. 30, No. 4,pp. 8-20, July 2014, incorporated herein by reference in its entirety).A high-efficiency ballistic electrostatic generator utilizingmicrodroplets has been developed. (See Y. Xie, D. Bos, L. J. de Vreede,H. L. de Boer, M.-J. Van der Meulen, M. Versluis, A. J. Sprenkels, A.Van den Berg, and J. C. T. Eijkel, “High-efficiency ballisticelectrostatic generator using microdroplets,” Nature Communications,Vol. 5, p. 3575, April 2014. [Online]. Available:http://dx.doi.org/10.1038/ncomms4575, incorporated herein by referencein its entirety). In the field of energy harvesting, an electrostaticgenerator known as a “doubler of electricity,” was developed as anenergy harvesting device and a battery charger. (See A. Deihimi and M.E. S. Mahmoodieh, “Analysis and control of battery-integrated dc/dcconverters for renewable energy applications,” IET Power Electronics,Vol. 10, No. 14, pp. 1819-1831, 2017, incorporated herein by referencein its entirety).

Electrostatic generators have a wide range of applications, such asprecipitators, electrostatic air cleaning, inkjet printers,electrostatic painting, xerography, ion thrusters and ion accelerationin nuclear research. There have been investigations into applying anelectrostatic generator to rotational speed measuring usingelectrostatic sensing. (See L. Wang, Y. Yan, Y. Hu, and X. Qian,“Rotational speed measurement through electrostatic sensing andcorrelation signal processing,” IEEE Transactions on Instrumentation andMeasurement, Vol. 63, No. 5, pp. 1190-1199, May 2014, incorporatedherein by reference in its entirety).

A DC-to-DC converter is a type of electric power converter whichconverts a DC source voltage from one level to another. The DC to DCconverter is an elemental circuit block in many electrical devices. Itis an essential part of modern system development to maximize the energyharvest for photovoltaic systems and wind turbines. Before thedevelopment of power semiconductors, conversion of a DC voltage from onelevel to another was through the conversion of a DC voltage to AC thenback again to DC. Consequently, these converters were relativelyinefficient and expensive due to the uses of different electriccomponents and conversion losses. The introduction of powersemiconductors and integrated circuits made it economically viable touse different techniques to acquire the needed voltage level, forinstance, converting DC power to high-frequency AC through the usage ofsemiconductors. Since the transformer voltage is a function offrequency, by feeding the generated high-frequency AC to a transformer,a high level AC voltage can be obtained. A rectifier circuit is thenused to convert the voltage back to DC.

Many electronic devices, such as cellular phones and laptop computers,powered by batteries use DC to DC converters. These electronic devicesoften have several sub-circuits, each with its voltage level, which canbe different from the voltage supplied by the battery or an externalsupply. As the energy drains from the battery, the voltage leveldeclines. Therefore, DC to DC converters using high-frequency switchingoffer a method to increase voltage from a partially lowered batteryvoltage thereby saving space instead of using multiple batteries toaccomplish the same thing.

There is an advantage in utilizing many small DC-AC converters versususing a single DC-AC converter in residential photovoltaic systems (PV).(See G. R. Walker and P. C. Sernia, “Cascaded DC-DC converter connectionof photovoltaic modules,” IEEE Transactions on Power Electronics, Vol.19, No. 4, pp. 1130-1139, July 2004, incorporated herein by reference inits entirety). The main disadvantage of a PV system is its variablevoltage. This was addressed by a Matlab based model for an intermediateDC-DC converter which increases the efficiency of the system byproviding an impedance match between the PV system and load (See M.Marodkar, S. Adhau, M. Sabley, and P. Adhau, “Design and simulation ofDC-DC converters for photovoltaic system based on matlab,” in 2015International Conference on Industrial Instrumentation and Control(ICIC), May 2015, pp. 1478-1483, incorporated herein by reference in itsentirety).

A comprehensive review demonstrated various high-voltage gain DC-DCconverter topologies, control strategies, and recent trades. (See V. B.Savakhande, C. L. Bhattar, and P. L. Bhattar, “Voltage-lift DC-DCconverters for photovoltaic application-a review,” in 2017 InternationalConference on Data Management, Analytics and Innovation (ICDMAI),February 2017, pp. 172-176, incorporated herein by reference in itsentirety). Different topologies having high voltage conversion ratio,low cost, and high-efficiency performance were classified into severalcategories. To optimize the output power of a photovoltaic system, itmust operate at the maximum power point (MPP). The MPPT algorithmincreases output power, and commonly works with a DC-DC converter.Additionally, an analysis and the essential features of differenttopologies of DC-DC converters were designed and simulated for solarphotovoltaic (PV) applications. Moreover, two conventional MPPTalgorithms were evaluated by computer simulation to analyze theirefficiency in different environmental conditions. (See L. A. Soriano, P.Ponce, and A. Molina, “Analysis of DC-DC converters for photovoltaicapplications based on conventional MPPT algorithms,” in 201714thInternational Conference on Electrical Engineering, Computing Scienceand Automatic Control (CCE), October 2017, pp. 1-6, incorporated hereinby reference in its entirety).

A high step-up DC-DC converter was reconfigured and integrated withconventional DC-DC converters and a battery. The reconfiguration of abattery-integrated DC-DC converter, BICs, with the linear quadraticregulator (LQR), was verified through simulations and experimentalresults. (See A. Deihimi and M. E. S. Mahmoodieh, “Analysis and controlof battery-integrated dc/dc converters for renewable energyapplications,” IET Power Electronics, Vol. 10, No. 14, pp. 1819-1831,2017, incorporated herein by reference in its entirety). Ahigh-efficiency DC-DC converter with high voltage gain based on coupledinductors, intermediate capacitor, and leakage energy recovery schemewas developed, using mutual coupling between conductors to store energyin a magnetic field. The mutually coupled conductors are connected tocapacitors at the output stage in a lossless manner. This highefficiency and high gain converter has an efficiency of 96% for lowoutput voltage sources. (See M. Das and V. Agarwal, “Design and analysisof a high-efficiency DC-DC converter with soft switching capability forrenewable energy applications requiring high voltage gain,” IEEETransactions on Industrial Electronics, Vol. 63, No. 5, pp. 2936-2944,May 2016, incorporated herein by reference in its entirety).

A high-voltage gain DC-DC converter for PV systems was shown to increasevoltage up to 311 V at maximum power. This converter utilized coupledconductors and sets of capacitors and semiconductors, and is suitablefor low input voltages and low-power applications. (See A. A. A.Freitas, F. L. Tofoli, E. M. S. Júnior, S. Daher, and F. L. M. Antunes,“High-voltage gain dc-dc boost converter with coupled inductors forphotovoltaic systems,” IET Power Electronics, Vol. 8, No. 10, pp.1885-1892, 2015, incorporated herein by reference in its entirety). Amulti-port high-voltage-gain DC-DC converters with two boost stages atthe input is known, in which the output voltage is twenty times theinput voltage. (See V. A. K. Prabhala, P. Fajri, V. S. P. Gouribhatla,B. P. Baddipadiga, and M. Ferdowsi, “A DC-DC converter with high voltagegain and two input boost stages,” IEEE Transactions on PowerElectronics, Vol. 31, No. 6, pp. 4206-4215, June 2016, incorporatedherein by reference in its entirety). A soft-switching DC-DC converterfor renewable energy conversion systems with solar PV cell or fuel cellstack as an input to achieve zero-voltage switching (ZVS) a turn-on foractive switches and zero-current switching (ZCS), a turn-off for fastrecovery diodes is known. This converter is described to achieve highstep-up voltage conversion ratio by utilizing a boost converter and avoltage-doubler configuration with a coupled inductors. (See B. R. Linand J. Y. Dong, “New zero-voltage switching DC-DC converter forrenewable energy conversion systems,” IET Power Electronics, Vol. 5, No.4, pp. 393-400, April 2012, incorporated herein by reference in itsentirety).

A high-efficiency dual-mode resonant converter topology with a detailedtheoretical analysis of the converter operation and its DC gain featureswas developed. (See Z. Liang, R. Guo, J. Li, and A. Q. Huang, “Ahigh-efficiency pv module-integrated DC/DC converter for PV energyharvest in FREEDM systems,” IEEE Transactions on Power Electronics, Vol.26, No. 3, pp. 897-909, March 2011, incorporated herein by reference inits entirety). Additionally, a converter was developed which canmaintain high efficiency for a wide input range at different outputpower levels by changing resonant modes depending on the panel operationconditions. Integrating a switched capacitor and a switched coupledinductor, into one converter increased the voltage gain, such that thedeveloped DC-DC converter configuration demonstrated an efficiency of93.6% at full load. (See S. M. Chen, M. L. Lao, Y. H. Hsieh, T. J.Liang, and K. H. Chen, “A novel switched-coupled-inductor DC-DC step-upconverter and its derivatives,” IEEE Transactions on IndustryApplications, Vol. 51, No. 1, pp. 309-314, January 2015, incorporatedherein by reference in its entirety). A DC-DC converter with highvoltage gain, zero current switching of the main switch, and low voltagestress of the main switches is known. This converter has a high voltagegain, and employs fewer components than a traditional converter. (See “Anovel switched-coupled-inductor DC-DC step-up converter and itsderivatives,” IEEE Transactions on Industry Applications, Vol. 51, No.1, pp. 309-314, January 2015, incorporated herein by reference in itsentirety). A high-conversion-ratio bidirectional DC-DC converter withmaximum efficiency reaching up to 96.41% was developed by utilizingcoupled inductors with a lower turn ratio, and high conversion ratio.(See H. Liu, L. Wang, Y. Ji, and F. Li, “A novel reversal coupledinductor high-conversion-ratio bidirectional DC-DC converter,” IEEETransactions on Power Electronics, Vol. 33, No. 6, pp. 4968-4979, June2018, incorporated herein by reference in its entirety). An interleavedboost converter was shown to achieve high step-up voltage conversionratio with a maximum efficiency of 94.5%. (See Y. T. Chen, Z. X. Lu, R.H. Liang, and C. W. Hung, “Analysis and implementation of a novel highstep-up DC-DC converter with low switch voltage stress and reduced diodevoltage stress,” IET Power Electronics, Vol. 9, No. 9, pp. 2003-2012,2016, incorporated herein by reference in its entirety). A bidirectionalDC-DC converter utilizing only two switches and LC resonant transformercapable of controlling the power flow with high efficiency of 92% isknown. (See M. Ishigaki, J. Shin, and E. M. Dede, “A novel softswitching bidirectional DC-DC converter using magnetic and capacitivehybrid power transfer,” IEEE Transactions on Power Electronics, Vol. 32,No. 9, pp. 6961-6970, September 2017, incorporated herein by referencein its entirety). A converter which utilizes the techniques ofswitched-capacitor, coupled-inductor, and multiplier capacitor toachieve the high voltage gain was developed. (See Y. T. Chen, Z. X. Lu,and R. H. Liang, “Analysis and design of a novel high-step-up DC-DCconverter with coupled inductors,” IEEE Transactions on PowerElectronics, Vol. 33, No. 1, pp. 425-436, January 2018, incorporatedherein by reference in its entirety). In S. Du et al. (2016), multilevelDC-DC converters were presented, for interconnecting medium-voltage DCnetworks. (See S. Du, B. Wu, K. Tian, D. Xu, and N. R. Zargari, “A novelmedium-voltage modular multilevel DC-DC converter,” IEEE Transactions onIndustrial Electronics, Vol. 63, No. 12, pp. 7939-7949, December 2016,incorporated herein by reference in its entirety). A multi-input DC-DCconverter with a control method for hybrid electric vehicles to enhancethe efficiency and performance of the converter was developed. (See R.R. Ahrabi, H. Ardi, M. Elmi, and A. Ajami, “A novel step-up multi-inputDC-DC converter for hybrid electric vehicles application,” IEEETransactions on Power Electronics, Vol. 32, No. 5, pp. 3549-3561, May2017, incorporated herein by reference in its entirety). Additionally, amulti-input DC-DC converter was developed as a solution for galvanicisolation for AC-DC utilizing an isolation transformer. (See H. L. Jou,J. J. Huang, J. C. Wu, and K. D. Wu, “Novel isolated multilevel DC-DCpower converter,” IEEE Transactions on Power Electronics, Vol. 31, No.4, pp. 2690-2694, April 2016, incorporated herein by reference in itsentirety). Further, a compact and lightweight design of onboard EVcharger which uses a bidirectional AC-DC single-stage converter wasdeveloped. (See U. R. Prasanna, A. K. Singh, and K. Rajashekara, “Novelbidirectional single-phase single-stage isolated ac dc converter withpfc for charging of electric vehicles,” IEEE Transactions onTransportation Electrification, Vol. 3, No. 3, pp. 536-544, September2017, incorporated herein by reference in its entirety).

Whether in energy harvesting or renewable energy sources, the workingprinciples of the above electrostatic generators are based on mechanicalforce, either moving a belt, microdroplets or rotating capacitor plates,to move a medium, liquid or solid, which converts charges to a higherpotential. Thus, they have lower efficiency, are bulky, and it isdifficult to control the quantities of charges produced. It is clearfrom the vast range of applications of an electrostatic generator, thata highly efficient and reliable electrostatic generator is needed.

The Static Electrostatic Generator (SEG) of the present disclosureconverts electrical energy at a low potential to a high potential.Consequently, the device can operate as a DC to DC voltage converter.Furthermore, the SEG can function as an electrostatic generator, similarto a Van de Graff generator, but unlike prior electrostatic generators,the device input and output energy of the SEG is purely electricalenergy. The electrostatic generator of the present disclosure has aconversion efficiency of up to 48% when converting mechanical energy toelectrical energy.

SUMMARY

In an exemplary embodiment, a static electrostatic generator (SEG)comprises a conductive metal wire having a first and a second end, acylindrical conductive metal sheet coaxial with the metal wire, thecylindrical conductive metal sheet having a first end and a second end,an interior surface and an exterior surface, a conductive metal spheresurrounding the conductive metal wire and the cylindrical conductivemetal sheet, the conductive metal sphere having an interior surface andan exterior surface, wherein the interior surface of the conductivemetal sphere is evenly spaced from the exterior surface of thecylindrical conductive metal sheet. A first switch, a second switch anda third switch, each switch having a first side and a second side areincluded, as is a battery having a first electrode and a secondelectrode, wherein the first electrode is connected to the first end ofthe metal wire and the second electrode is attached to the first side ofthe first switch, wherein the second side of the first switch isconnected to the first end of the cylindrical conductive metal sheet.Further included are a second switch having its first end connected tothe second end of the conductive metal wire and its second end connectedto the second end of the cylindrical conductive metal sheet and a thirdswitch having its first end connected to the cylindrical conductivemetal sheet and its second end connected to the interior surface of theconductive metal sphere. The SEG has a controller connected to each ofthe switches and including timing circuitry configured to operate theswitches at specified times in order to generate static electrostaticcharges on the surface of the metal sphere.

In another exemplary embodiment, a method of generating staticelectrostatic charges, is described, comprising connecting a first endof a conductive metal wire to a first battery electrode; connecting afirst switch between a second battery electrode and a first end of acylindrical conductive metal sheet; connecting a second switch between asecond end of the conductive metal wire and a second end of thecylindrical conductive metal sheet; connecting a third switch betweenthe cylindrical conductive metal sheet and a conductive metal sphere;closing, by a controller, the first switch; opening, by the controller,the first switch; closing, by the controller, the second switch and thethird switch; wherein closing the second and third switches causes theconductive metal sphere to accumulate electrostatic charges; dischargingthe conductive metal sphere; and opening, by the controller, the secondswitch and third switch.

The foregoing general description of the illustrative embodiments andthe following detailed description thereof are merely exemplary aspectsof the teachings of this disclosure, and are not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of this disclosure and many of theattendant advantages thereof will be readily obtained as the samebecomes better understood by reference to the following detaileddescription when considered in connection with the accompanyingdrawings, wherein:

FIG. 1 is the internal construction of the SEG;

FIG. 2A is an illustration of the SEG with electrical components.

FIG. 2B is an illustration of a patterned metal sphere.

FIG. 3 is an exemplary controller which may be used with the SEG.

FIG. 4A is a graph illustrating the electric field mesh selection forsimulation of the SEG;

FIG. 4B is a graph illustrating the electric field interaction of theSEG;

FIG. 5 illustrates the cross section of the inner and outer conductorsof the device;

FIG. 6 illustrates the electric potential distribution of the device;

FIG. 7 illustrates the electric field distribution of the device;

FIG. 8 illustrates the electric potential distribution of the devicewhen ε_(r)=10;

FIG. 9 illustrates the electric field distribution of the device whenε_(r)=10;

FIG. 10 illustrates the electric potential distribution of the devicewhen the voltage is halved;

FIG. 11 illustrates the electric field distribution of the device whenthe voltage is halved;

FIG. 12 illustrates the electric potential distribution of the devicewhen the diameter of the thin wire is doubled;

FIG. 13 illustrates the electric field distribution of the device whenthe diameter of the thin wire is doubled;

FIG. 14 illustrates the electric potential distribution of the device;

FIG. 15 illustrates the electric field distribution of the device;

FIG. 16 illustrates the electric potential distribution of the device;and

FIG. 17 illustrates the electric field distribution of the device.

FIG. 18 is an illustration of a non-limiting example of a controller,according to certain embodiments.

FIG. 19 is an exemplary schematic diagram of a data processing system,according to certain embodiments.

FIG. 20 is an exemplary schematic diagram of a processor, according tocertain embodiments.

DETAILED DESCRIPTION

In the drawings, like reference numerals designate identical orcorresponding parts throughout the several views. Further, as usedherein, the words “a,” “an” and the like generally carry a meaning of“one or more,” unless stated otherwise. The drawings are generally drawnto scale unless specified otherwise or illustrating schematic structuresor flowcharts.

Furthermore, the terms “approximately,” “approximate,” “about,” andsimilar terms generally refer to ranges that include the identifiedvalue within a margin of 20%, 10%, or preferably 5%, and any valuestherebetween.

Aspects of the present disclosure describe a static electrostaticgenerator (SEG) and a method for operating a static electrostaticgenerator.

An overview of the SEG follows.

The internal elements of the SEG (100) are a thin metal wire 120 and acylindrical metal sheet 110. The cylindrical metal sheet 110 is spacedapart from the thin metal wire by a first distance, d₁, as shown incut-out in FIG. 1 . Upon application of a voltage (provided by battery240 in FIG. 2A), negative charges build up on the surface of the wire120, and corresponding positive charges form on the cylindrical metalsheet 110. The cylindrical metal sheet surrounds the thin metal wire asshown in FIGS. 1 and 2 .

As shown in the FIG. 2A, the SEG (200) includes a surrounding metalsphere 230, shown in cut-out in FIG. 2A for clarity, at a distance d₂from the cylindrical metal sheet 210. Three switches S1, S2, and S3 areused to operate the device. The switches are electronic switches, suchas transistors, electrically actuated switches, or electrically actuatedmechanical switches. The switch S3 can be replaced by a diode insituations where only one type of charge, positive or negative, isgenerated. A controller, 250, controls the switching processes of allthe switches.

During a ramp up step, the controller sends a signal to close S1 at timeτ₁, thus charging the metal wire 220 with negative charges and the metalcylinder 210 with positive charges. The charging time of both conductorsmust be considered, otherwise, the efficiency of the generated chargeswill be lower. Once the two metals are charged, at time τ₂, thecontroller switches S1 OFF. Since there is no complete circuit when S1is OFF, the charges are stored on the cylindrical metal sheet and thinwire. At time τ₃, the controller switches S2 and S3 ON.

Switching S1 OFF and S2 and S3 ON drives the positive charges to themetal sphere 230. The time required for the discharge of the cylindricalmetal sheet 210 to the metal sphere 230 is related to the capacitancebetween the two conductors and the resistance of the line between themwhen S2 is connected. S2 and S3 must be turned OFF before the operationrestarts by reconnecting S1.

In an aspect, the switches may be transistor switches, selected from thegroup consisting of MOSFETS, JFETS and FETs. The transistors must havehigh breakdown voltage ratings sufficient to withstand the high supplyvoltage, typically in the range of 500-1000 volts. In a non-limitingexample, a MOSFET transistor may be of the type IXTF1N450 sold by MouserElectronics, 1000 North Main Street, Mansfield, Tex. 76063, USAhttps://www.mouser.com/ProductDetail/IXYS/IXTF1N450?qs=%2fha2pyFaduj6YwmeOD9vmb2P8sa3TZXSO%252bkvuue8xqUGVsVuTXJ2Cw%3d%3d.

In an aspect, the thin metal wire, cylindrical metallic sheet and themetal sphere are selected from the group consisting of copper, aluminum,tantalum, brass and gold. The thicknesses of the cylindrical metal sheetand the metal sphere must be great enough to structurally support theirlengths respectively. The thickness of the cylindrical metal sheet is inthe range of 0.016 to 6.35 mm, preferably 0.05 to 2 mm, more preferably0.075 to 1.5 mm, even more preferably 0.1 to 0.125 mm. The thickness ofthe metal sphere is in the range of 0.1 to 6.35 mm, preferably 0.25 to3.0 mm, more preferably 1 to 2 mm, even more preferably 1.5 mm.

The metal sphere may be patterned with stripes or blocks of differentmaterials. The patterns may be stripes around the sphere or blocks ofmetal at locations on the sphere to focus the static charge at outputpoints. The charge density of a material is Q=σA, where σ is theelectrical conductivity of the material. For example, the conductivityof copper is 5.98×10⁷ Sm⁻¹ at 20 degrees C. and the conductivity of goldis 4.52×10⁷ Sm⁻¹ at 20 degrees Celsius. In a non-limiting example, agold sphere patterned with stripes of copper has a higher surface chargeat the stripes than on the copper areas, as shown in FIG. 2B(a). In thisconfiguration, the stripes provide contact points for the output of thestatic charges. In a further non-limiting example, the pattern may beblocks of copper on a gold sphere, which provide a base for adhering aconductive probe (not shown) which uses the static charges as shown inFIG. 2B(b). Alternatively, the pattern may be dots or circular patterns(not shown). The charge density at the copper pattern may be as much as30% higher than the charge density at an unpatterned location.

The thin metal wire used in the descriptive embodiments has a radius inthe range of 0.001 to 2.0 mm, preferably 0.001 to 1.0 mm, morepreferably 0.01 to 0.16 mm, even more preferably 0.04 to 0.08 mm.However, if the invention is fabricated in a larger scale, the thinmetal wire may have a larger radius, so as to handle the larger voltageneeded to charge a larger metallic cylinder of the SEG. Additionally,the thin metal wire must be of material and great enough radius tostructurally support the wire within the cylindrical metal sheet. In anon-limiting example, the radius of the metal cylinder is 1 mm and thelength of the metal cylinder and thin wire is 10 mm.

In an aspect, an exemplary controller 250/350 is shown in FIGS. 2A, 3 .The SEG design can be scalable, therefore different charging anddischarging times and different high DC voltage levels can be used, thusthe electrical circuit controller, wire gauges, and switch types must beconsidered in designing a larger SEG. Although a battery 240 is shown inFIG. 2A, the battery can be integrated into the controller 250, whereinthe battery voltage is provided by a switchable DC power supply.

As mentioned above, the controller turns the switches ON and OFF atspecific timing intervals. The memory 370 may be store timing settingsfor the switches as entered by a user at I/O Interface 390. The I/OInterface 390 may have controllable buttons (1, 2, 3) which enable auser to easily set the timing of the switches S1, S2 and S3.Alternatively, the microprocessor 380 may receive charge measurementsfrom a sensor on the surface of the metal sphere and adjust the timingof the switches and voltage based on the measurements.

In an aspect of the present disclosure, the battery 240 is a high DCvoltage source or a battery with a high DC-DC voltage converter.

In an aspect of the present disclosure, the electrostatic generator(SEG) is small, lightweight, easy to manufacture, and scalable. The SEGcan be resized to generate electrostatic charges more efficiently withdifferent voltage levels. Additionally, the SEG is reliable as it doesnot depend on mechanical movement to generate static charges. Moreover,the SEG produces charges in controllable quantities. The SEG has anefficiency of up to 46.95%, which is among the highest in the field ofelectrostatic generation. Also, the SEG does not require any gas orliquid to be under high pressure to generate the charges with highefficiency. The device can be used as a DC-DC converter however with anefficiency of 46.95%, even though the device is neither required toinclude an inductor, which means it is not temperature sensitive, normust it utilize many capacitors to achieve the same high voltage levelrequired by different applications.

As shown in FIG. 1 , the internal elements of the SEG, having a thinwire 120 and a cylindrical metal sheet 110 surrounding the thin wire,are similar to a coaxial cable construction. There is a dielectricmaterial 125 between 120 and 110. For clarity, the dielectric materialis indicated but not shown within the interior of the cylinder.

Initial conditions are as such:

-   -   1) there should be no charges on any of the conductors, i.e. the        conductors should be grounded initially to remove all charges,    -   2) the dielectric material should have no dipoles, and    -   3) the applied voltage should be a DC Voltage.

The first embodiment is illustrated in FIGS. 2A, 3 and 5 . In the firstembodiment, a static electrostatic generator (SEG) is described whichcomprises a thin conductive metal wire 220 having a first and a secondend; a cylindrical conductive metal sheet 210 coaxial with the metalwire, the cylindrical conductive metal sheet having a first end and asecond end, an interior surface and an exterior surface; a conductivemetal sphere 230 surrounding the conductive metal wire and thecylindrical conductive metal sheet, the conductive metal sphere havingan interior surface and an exterior surface, wherein the interiorsurface of the conductive metal sphere is evenly spaced from theexterior surface of the cylindrical conductive metal sheet (see FIG. 5).

The SEG has a first switch S1, a second switch S2 and a third switch S3,each switch having a first side and a second side; a battery having afirst electrode and a second electrode, wherein the first electrode isconnected to the first end of the metal wire and the second electrode isattached to the first side of the first switch. The second side of thefirst switch is connected to the first end of the cylindrical conductivemetal sheet. The second switch has its first end connected to the secondend of the conductive metal wire and its second end connected to thesecond end of the cylindrical conductive metal sheet. The third switchhas its first end connected to the cylindrical conductive metal sheetand its second end connected to the interior surface of the conductivemetal sphere.

A controller 250 is connected to each of the switches and includestiming circuitry 360 configured to operate the switches at specifiedtimes in order to generate electrostatic charges on the surface of themetal sphere.

There is an optional dielectric material between the conductive metalwire and the cylindrical conductive metal sheet. This dielectricmaterial has relative permittivity, ε_(r), in the range of 1-10, and isselected from the group consisting of air, PTFE, polyethylene, polymide,polypropylene, polystyrene, aluminum oxide, ceramic, mica and glass. Theoptional dielectric material may be used to support the wire within thecylindrical conductive metal sheet.

The thin metal wire has a radius in the range of 0.001 to 2.0 mm,preferably 0.001 to 1.0 mm, more preferably 0.01 to 0.16 mm, even morepreferably 0.04 to 0.08 mm.

The thin metal wire, cylindrical metallic sheet and the metal sphere areselected from the group consisting of copper, aluminum, tantalum, brassand gold.

The switches are selected from the group consisting of transistors,electrically actuated switches, or electrically actuated mechanicalswitches. When the switches are transistors, the transistors arepreferably high power MOSFETS, but may optionally be selected from thegroup consisting of MOSFETS, JFETS, FETs, and bi-polar junctiontransistors (BJT).

The controller 350 includes a timing module connected to the switchesand a microprocessor 380 connected to the timing module, themicroprocessor having circuitry configured to control the timing moduleto turn the switches ON or OFF.

The battery may be a battery bank having a plurality of internal,switchable batteries. In this option, the controller has circuitryconfigured to adjust the voltage applied to the battery by switching theinternal batteries of the battery bank to add or delete them fromcontributing to the voltage at the battery electrodes.

An optional voltage sensor 202 may be located on the external surface ofthe metal sphere and connected to the controller. The voltage sensor maybe configured to make voltage measurements of the external surface ofthe metal sphere and send the measurements to the controller. Thecontroller may use these measurements to set the switch timing.Alternatively, the switch timing may be entered at I/O interface 390(see FIG. 3 ) for use by microprocessor 380.

A second embodiment to a method of generating static electrostaticcharges is illustrated with respect to FIGS. 2A, 3, and 5 . The methodcomprises connecting a first end of a thin conductive metal wire 220 toa first battery 240 electrode; connecting a first switch S1 between asecond battery electrode and a first end of a cylindrical conductivemetal sheet 210; connecting a second switch S2 between a second end ofthe conductive metal wire and a second end of the cylindrical conductivemetal sheet; connecting a third switch between the cylindricalconductive metal sheet 210 and a conductive metal sphere 230.

The method includes operating the SEG by closing, by a controller 250,the first switch S1; opening, by the controller, the first switch,closing the second switch S2 and the third switch S3; wherein closingthe second and third switches causes the conductive metal sphere toaccumulate electrostatic charges. After a period of time, the second andthird switches are opened. The first switch may again be closed, toaccumulate a higher level of charge on the metal cylinder. After adesignated charging time, the first switch is opened and the second andthird switches are closed to accumulate more charge on the conductivemetal sphere. After two charging sessions, the conductive metal spheremay be discharged by opening the second switch and third switch, andcontacting the conductive metal sphere with a conductor (not shown).

The electrical polarity of the battery electrodes is operativelyreversible, therefore either positive or negative charges can build onthe conductive metal sphere. The controller is connected to the batteryelectrodes such that reversing the polarity of the battery electrodes,reverses the polarity of the electrostatic charges which accumulate onthe surface of the metal sphere.

The battery 240 is optionally a battery bank having a plurality ofinternal, switchable batteries. In this option, the controller isconnected to the internal batteries such that switching the internalbatteries adjusts the voltage level of the battery.

The method includes measuring, by a voltage sensor 202, the voltage onan external surface of the metal sphere 230 and switching, by thecontroller, the internal batteries based on the voltage measurements toachieve a desired voltage input to the static electrostatic generator.

The method includes using a timing module 360 which is connected to amicroprocessor 380 in the controller 350. The timing includes closing,by the timing module of the controller, the first switch at a time τ₁,wherein closing the first switch causes equal and opposite charges toaccumulate on the surfaces of the thin metal wire and the cylindricalmetal sheet; opening the first switch at a time τ₂, wherein τ₂ isgreater than τ₁; then closing, by the controller, the second switch andthe third switch at a time τ₃, wherein τ₃ is greater than τ₂.

The conductive metal sphere accumulates electrostatic charges from timeτ₃ to time τ₄, wherein τ₄ is greater than τ₃. After τ₄ has passed, thesecond switch and third switch are opened and the conductive metalsphere may be discharged between times τ₄ and τ₅, where τ₅ is greaterthan τ₄. To discharge the conductive metal sphere, a conductor connectedto ground or another device (not shown) may contact the conductive metalsphere.

Alternatively, the conductive metal sphere may be charged to a highercharge level by repeating the steps of closing the first switch. Attime, τ₆, the first switch is opened and the second switch and thirdswitch are again closed, which allows more charges to accumulate on thesphere. As the static electrostatic generator is used to produceelectrostatic charges for purposes outside of the scope of the presentdisclosure, using the charges discharges the metal sphere. Whencontacted by a conductor, the sphere discharges until time τ₇ Thecontroller then acts by opening the second switch and third switch attime τ₈.

The time τ₄ may be determined by the timing module 360. Alternatively,determining time τ₄ may be based on the voltage sensor measurements,wherein τ₄ is the time at which the voltage measurement is greater thana first threshold. The first threshold may be set at the I/O interfaceand is stored in a memory 370. The first threshold may preferably be setto be 10% less than the voltage level of the battery.

The opening, by the controller, of the second switch and third switch attime 15, may also be determined by the time at which the voltagemeasured by the voltage sensor is less than a second threshold. Thesecond threshold may be set at the I/O interface and stored in a memory370. This second threshold may preferably be set to be 90% less than thevoltage level of the battery.

The times τ₁, and τ₃, are received from an I/O interface 390 connectedto the controller. The I/O interface may have buttons configured tocontrol the switches manually.

The thin metal wire and conductive metal cylinder have known dimensions.The thin metal wire has a length L₁ and a radius r₁ and the cylindricalmetal sheet has a length L₂ and a radius r₂. In the current embodiment,L₁=L₂, but may optionally have different lengths, which would affect thecapacitance between the thin metal wire and conductive metal cylinder.

The microprocessor 380 of the controller has analysis circuitryconfigured for calculating the capacitance, which is based on thelengths L₁ and L₂ and the radii r₁ and r₂. The method includescalculating the time constant based on the capacitance and determiningthe time τ₂ based on the sum of the time τ₁ and five time constants.

The capacitance is calculated based on the equation:

$C = \frac{2{\pi\varepsilon}0L}{\ln\left( {r{2/r}1} \right)}$where ε₀=1 for a vacuum, and is otherwise a known specification of theoptional dielectric between the wire and the metal sheet. A timeconstant is calculated as the resistance times the capacitance. In thiscase, the resistance is provided by the resistance of the battery. Fivetime constants determine the amount of time necessary to fully dischargea capacitor. (See “Cylindrical Capacitor”,http://www.phys.uri.edu/gerhard/PHY204/tsl105.pdf, incorporated hereinby reference in its entirety).

The discharge time τ₇ depends on the resistance of the conductortouching the metal sphere and is determined experimentally based on theamount of discharging resistance.

In general, when the cylindrical metal sheet is connected to a positivevoltage source, and the metal wire is connected to a negative voltagesource, the charges start to accumulate on the surfaces of theconductors. Since the surface area of the thin metal wire is muchsmaller than the surface area of the cylindrical metal sheet, morecharge will accumulate on the cylindrical metal sheet. After chargingboth conductors with different amount of charges due to the surface areageometric differences between them, switch S1 is opened and the switchesS2 and S3 are closed (see FIG. 2A). By closing S2, the number of chargeson the thin wire will cancel the same number of charges on thecylindrical metal sheet. Since the electric field binding the remainingextra charges on the cylindrical metal sheet is gone when S2 and S3 areconnected, the remaining charges on the cylindrical metal sheet are setfree. Thus the number of free charges can be calculated byQ _(Free) =Q _(Cylindrical-Metal-Sheet) −Q _(Wire)  (1)

The free charges cannot move to the thin wire since the static chargesare not allowed to be inside a metal. The metal sphere 230 acts as acharge collector as no static charges are allowed to exist inside aconductor. Charges on the metal sphere start to accumulate once theswitches S2 and S3 are closed while S1 is opened. The metal sphere 230prevents any voltage difference across S1 except for the batteryvoltage. Any enclosing metal surface will be sufficient to act as chargeaccumulator surface, whether spherical or cylindrical.

To estimate the SEG efficiency, firstly, the total energy stored (TES)within the SEG after it is fully charged must be calculated. Forcing thenumber of charges on the cylindrical metal sheet to equal the number ofcharges on the thin wire, the energy lost (EL) can be calculated. Thus,the efficiency, η, will be:

$\begin{matrix}{\eta = {\frac{{TES} - {EL}}{TES}*100}} & (2)\end{matrix}$

The SEG of the present disclosure has many advantages over existingelectrostatic generators. It is capable of fast charge generation byutilizing fast switching transistors. Additionally, the SEG can generateeither positive or negative charges by merely reversing the batterypolarity. Moreover, it can control the number of charges generated bycontrolling the voltage and the switching time of the switches, such astransistors. Furthermore, no mechanical methods are required to generatethe charges, thus is a static device. The efficiency of the SEG is ashigh as 46.95%, as will be shown in the results section where manydifferent scenarios were tested to determine the device output andefficiency.

Simulation of the SEG is carried out in MATLAB using the FiniteDifference Method (FDM), and the FEMM (Finite Element Method Magnetics),then using a Finite element Method (FEM), showing the results arecomparable. (See D. C. Meeker, “Finite element method magnetics,”Version 4.2, 2015, incorporated herein by reference in its entirety).

One of the numerical solutions used in simulating the SEG is the Finitedifference method, FDM. FDM is one of the numerical solution methodsused to solve complex problems that are difficult to solve analyticallyor by linearizing differential equations. (See M. N. Sadiku, NumericalTechniques in Electromagnetics with MATLAB. CRC Press, Apr. 9, 2009,incorporated herein by reference in its entirety). It is a numericalapproximation solution that converts differential equations to finitedifference equations, and through iterations of algebraic equations, asolution of a complex differential equation can be obtained. (See J. D.Kraus, Electromagnetics. McGraw-Hill Companies, Jul. 1, 1992; and D. K.Cheng, Field and Wave Electromagnetics. Addison-Wesley EducationalPublishers Inc., 1983, each incorporated herein by reference in theirentirety).

Laplace's equation and Poisson's equation are powerful tools torepresent an electrostatic system. Solving these differential equationsfor complex geometry in order to represent the behavior of theelectrostatic model must be carried through a numerical solution. Thereare many methods of finite difference method can be applied to solve forLaplace's and Poisson's equations, the method used in the presentdisclosure for finite difference is the Five-point star (leapfrog). (SeeJ. R. Nagel, “Numerical solutions to Poisson equations using thefinite-difference method [education column],” IEEE Antennas andPropagation Magazine, Vol. 56, No. 4, pp. 209-224, August 2014; and M.N. Sadiku et al. (2009), each incorporated herein by reference in theirentirety).

A. LaPlace's Equation

To solve the differential equation of the SEG, the differential equationmust be converted to a finite difference equation∇·D=0  (3)sinceD=ε ₀ε_(r) E  (4)then

$\begin{matrix}{{\nabla{\cdot \left\lbrack {\varepsilon_{0}\varepsilon_{r}E} \right\rbrack}} = 0} & (5)\end{matrix}$ $\begin{matrix}{{\nabla^{2}V} = 0} & (6)\end{matrix}$ $\begin{matrix}{\nabla^{2}{= {\frac{\partial^{2}}{\partial x^{2}} + \frac{\partial^{2}}{\partial y^{2}} + \frac{\partial^{2}}{\partial z^{2}}}}} & (7)\end{matrix}$where D is the flux density and

D is the divergence of the flux density.

Permittivity describes the amount of charge needed to generate one unitof electric flux in a particular medium. Accordingly, a charge willyield more electric flux in a medium with low permittivity than in amedium with high permittivity. Permittivity c is the measure of amaterial's ability to store an electric field in the polarization of themedium. The permittivity of a dielectric medium is often represented bythe ratio of its absolute permittivity to the electric constant. Thisdimensionless quantity is called the relative permittivity of themedium, sometimes also called “permittivity”. Relative permittivityε_(r) is also commonly referred to as the dielectric constant. Thepermittivity in a vacuum is denoted by co. The relative permittivity isrelated to the permittivity and the permittivity in a vacuum by theexpression: ε_(r)=ε/ε₀.

Under the assumption that there are no changes in the z-components(lengths of the conductors), and the problem is to solve for x and y,based on:

$\begin{matrix}{{\nabla^{2}V} = {\frac{\partial^{2}V}{\partial x^{2}} + \frac{\partial^{2}V}{\partial y^{2}}}} & (8)\end{matrix}$

To solve the Laplace differential equation, first the area of interestfor study and simulation of the behavior of electrostatic field must bedivided into a fine mesh using the five-point star configuration shownin FIG. 4A. The mesh areas are plugged into equation (8) to yield:

$\begin{matrix}{\frac{\partial^{2}V}{\partial x^{2}} \cong \frac{V_{({{i + 1},j})} - {2V_{({i,j})}} + V_{({{i - 1},j})}}{h^{2}}} & (9)\end{matrix}$ $\begin{matrix}{\frac{\partial^{2}V}{\partial y^{2}} \cong \frac{V_{({i,{j + 1}})} - {2V_{({i,j})}} + V_{({i,{j - 1}})}}{h^{2}}} & (10)\end{matrix}$

Since the grid is uniform:

$\begin{matrix}{{\nabla^{2}V} = {\frac{V_{({{i + 1},j})} + V_{({{i - 1},j})} + V_{({i,{j + 1}})} + V_{({i,{j - 1}})} - {4V_{({i,j})}}}{h^{2}} = 0}} & (11)\end{matrix}$ $\begin{matrix}{V_{({i,j})} = {\frac{1}{4}\left\lbrack {V_{({{i + 1},j})} + V_{({{i - 1},j})} + V_{({i,{j + 1}})} + V_{({i,{j - 1}})}} \right\rbrack}} & (12)\end{matrix}$for varying dielectrics:

$\begin{matrix}{a_{0} = {{\varepsilon\left( {i,j} \right)} + {\varepsilon\left( {{i - 1},j} \right)} + {\varepsilon\left( {i,{j - 1}} \right)} + {\varepsilon\left( {{i - 1},{j - 1}} \right)}}} & (13)\end{matrix}$ $\begin{matrix}{a_{1} = {\frac{1}{2}\left\lbrack {{\varepsilon\left( {i,j} \right)} + {\varepsilon\left( {i,{j - 1}} \right)}} \right\rbrack}} & (14)\end{matrix}$ $\begin{matrix}{a_{2} = {\frac{1}{2}\left\lbrack {{\varepsilon\left( {{i - 1},j} \right)} + {\varepsilon\left( {i,j} \right)}} \right\rbrack}} & (15)\end{matrix}$ $\begin{matrix}{a_{3} = {\frac{1}{2}\left\lbrack {{\varepsilon\left( {{i - 1},{j - 1}} \right)} + {\varepsilon\left( {{i - 1},j} \right)}} \right\rbrack}} & (16)\end{matrix}$ $\begin{matrix}{a_{4} = {\frac{1}{2}\left\lbrack {{\varepsilon\left( {i,{j - 1}} \right)} + {\varepsilon\left( {{i - 1},{j - 1}} \right)}} \right\rbrack}} & (17)\end{matrix}$ $\begin{matrix}{{{{- a_{0}}{V\left( {i,j} \right)}} + {a_{1}{V\left( {{i + 1},j} \right)}} + {a_{2}{V\left( {i,{j - 1}} \right)}} + {a_{3}{V\left( {{i - 1},j} \right)}} + {a_{4}{V\left( {i,{j + 1}} \right)}}} = 0} & (18)\end{matrix}$ $\begin{matrix}{{V\left( {i,j} \right)} = {\frac{1}{a_{0}}\left\lbrack {{a_{1}{V\left( {{i + 1},j} \right)}} + {a_{2}{V\left( {i,{j - 1}} \right)}} + {a_{3}{V\left( {{i - 1},j} \right)}} + {a_{4}{V\left( {i,{j + 1}} \right)}}} \right\rbrack}} & (19)\end{matrix}$where V is the electric potential at a point in the simulation, h is thedistance between two points in the simulation, and as the simulation isdivided equally along the x-axis and y-axis, h_(x)=h_(y)=h. In equations(13)-(19), a₀ is the equivalent dielectric between four dielectricmaterials at point (i,j), a₁ is the equivalent dielectric between twodielectric materials at point (i+1 j), a₂ is the equivalent dielectricbetween the two dielectric materials at point (i,j−1), a₃ is theequivalent dielectric between the two dielectric materials at point(i−1,j) and a₄ is the equivalent dielectric between the two dielectricmaterials at point (i,j+1).

B. Poisson's Equation

By using Poisson's equation, the charges on each plate can becalculated, since∇·D=ρ _(c)  (20)where ρ_(c) is the surface charge density.

C. Electric Field

To calculate the electric field:

$\begin{matrix}{{{{- a_{0}}{V\left( {i,j} \right)}} + {a_{1}{V\left( {{i + 1},j} \right)}} + {a_{2}{V\left( {i,{j - 1}} \right)}} + {a_{3}{V\left( {{i - 1},j} \right)}} + {a_{4}{V\left( {i,{j + 1}} \right)}}} = {- \frac{Q\left( {i,j} \right)}{\varepsilon_{0}}}} & (21)\end{matrix}$ $\begin{matrix}{E = {- {\nabla V}}} & (22)\end{matrix}$ $\begin{matrix}{E = {{{- \hat{x}}\frac{\partial V}{\partial x}} - {\hat{y}\frac{\partial V}{\partial x}}}} & (23)\end{matrix}$ $\begin{matrix}{E = {{E_{x}\left( {i,j} \right)} + {E_{y}\left( {i,j} \right)}}} & (24)\end{matrix}$ $\begin{matrix}{{E_{x}\left( {i,j} \right)} = {- \frac{{V\left( {{i + 1},j} \right)} - {V\left( {i,j} \right)}}{h}}} & (25)\end{matrix}$ $\begin{matrix}{{E_{y}\left( {i,j} \right)} = {- \frac{{V\left( {i,{j + 1}} \right)} - {V\left( {i,j} \right)}}{h}}} & (26)\end{matrix}$where {circumflex over (x)} and ŷ denote the normalized vectors of x, y.

After obtaining the potential for each point on the unified mesh, theelectric field can be calculated using the gradient function in MATLAB.The magnitude of the net electric field can be calculated as

$\begin{matrix}{E = \sqrt{E_{x}^{2} + E_{y}^{2}}} & (27)\end{matrix}$

After obtaining the electric field, the energy for each cell in the meshcan be calculated using

$\begin{matrix}{{Energy} = {\frac{1}{2}\varepsilon_{0}E^{2}V_{cell}}} & (28)\end{matrix}$

FIG. 4B is a graph illustrating the electric field interaction of theSEG.

IV. Simulation Results

The simulation of the SEG was carried out in MATLAB using FDM and FEMMsoftware. The SEG and its dimensions are shown in FIG. 5 and Table 1.The column “Dimension of the simulated volume” refers to the electricfield/potential extents as graphed in FIG. 6-17 . Z is the length of themetal cylinder respectively, as used in the simulation.

TABLE 1 Parameters of the SEG and the simulation Dimension of thesimulated volume X [mm] Y [mm] Z [mm] 20 20 100 Device parameters r₁(mm)r₂(mm) r₃(mm) ε_(r) V_(DC)(Volt) 0.04 1 1.1 1 1000

As r₃ is only 0.1 mm greater than r₂, a structural support may be usedwithin the interior of the metal sphere to hold the metal sphere and thecylindrical metal sheet at the proper spacing. This structural supportmay be a dielectric which configured to provide structural support ofthe wire and cylindrical metal shield spacing. Any dielectric materialwith minimum thickness to withstand the applied voltage can be used tosupport the metal cylinder and the thin wire and insulate them from themetal sphere.

To determine the number of charges freed from the outer metal sheet, avoltage must be applied between the wire and the metal sheet (see Table2, Case 0). The difference in the number of charges between the wire andthe metal sheet, which is due to the area geometric difference betweenboth of the conductors, is the number of free charges.

The calculations used to determine the charges on the sphere are nowpresented.

The known constant values are the potential applied to each conductor.For simplicity, two spheres with different radii, a and b, andseparation distance d are used. The potential of a single sphere ofradius r is given by:

$V = \frac{Q}{4{\pi\varepsilon}_{0}r}$Since −V₁=V₂, (see battery 240, FIG. 2A) and the radii of spheres are aand b, then

$\frac{Q_{1}}{4{\pi\varepsilon}_{0}a} = \frac{Q_{2}}{4{\pi\varepsilon}_{0}b}$Therefore,

$Q_{2} = {Q_{1}\frac{b}{a}}$

If the radius b>a, then the amount of charge accumulated on the spherewith radius b is greater than the amount of charge accumulated on thesphere with radius a. This example shows that different geometricspheres with different areas could accumulate different charges. (See“Field and Wave Electromagnetics” book by David K. Cheng, chapter 3pages (104-105) ISBN: 0-201-01239-1, incorporated herein by reference inits entirety). A similar analysis applies to plane conductors withdifferent geometry as well as to cylindrical conductors. For thecylindrical capacitor of the present disclosure, the voltage is heldconstant, thus the amount of charge varies depending on the geometry ofthe thin wire and the metal cylinder. The electric field of acylindrical wire is given by:

$E = \frac{Q_{0}}{2{\pi\varepsilon}_{0}{Lr}}$where L is the length of the wire and r is the radius. Thus, the voltageis given by:

$V = {\frac{Q}{2{\pi\varepsilon}_{0}L}\ln r}$Since the voltages −V₁=V₂, and the radii of the thin wire and the metalcylinder are a and b respectively,

${\frac{Q_{1}}{2{\pi\varepsilon}_{0}L}\ln a} = {\frac{Q_{2}}{2{\pi\varepsilon}_{0}L}\ln b}$Therefore,

$Q_{2} = {Q_{1}\frac{\ln a}{\ln b}}$In a non-limiting example, simulation is performed using a=0.04 mm andb=1 mm. This yields:Q ₂=1.47Q ₁orQ ₁=0.68Q ₂Reference to Table 2 shows that the simulation of Case 0 results in:Q ₁=0.55Q ₂

The difference in the values are due to the numerical error associatedwith the simulation method. Increasing the number of points taken by thesimulation yields a result very close number to the analytical solution.

In design, the diameter of the thin wire should be as small as possiblefor optimum operation. The spacing between the thin metal wire and themetal cylinder is dependent on the applied voltage and the breakdownvoltage of the dielectric between the thin metal wire and the metalcylinder. For example, the break down voltage of air is 3 kV/mm,(dependent on temperature and humidity). Thus, the optimum distancebetween the thin wire and the metal cylinder is 1 mm if the appliedvoltage is 3 kV. The breakdown voltage is not an absolute value, as itis dependent on the temperature and humidity, thus during simulation theapplied voltage was set at 1 kV for 1 mm spacing. If the spacingincreases the voltage must increase as well to maintain the optimumoperation of the device.

FIG. 6 shows the electric potential distribution of the SEG. FIG. 7shows the electric field distribution of the SEG.

To estimate the efficiency of the SEG, an equal amount of the chargesare forced on both the wire and the metallic sheet, which is the numberof charges on the thin wire since those charges will be canceled outwith an equal number of charges on the metallic sheet. By comparing thetotal amount of energy stored within the SEG with the amount of energyassociated with an equal number of charges, the efficiency of the SEGcan be calculated. Thus by forcingQ ₂ =−Q ₁  (29)and by calculating the energy associated with the charges, theefficiency can be calculated, as shown in equation (2).A. Case I: The Effect of Dielectric Material

In this case, the dielectric material between the conductors is replacedwith a material which has ε_(r)=10, to study the effects on chargesproduction and the efficiency of the SEG, see Table 2 Case I. FIG. 8shows the electric potential distribution of the SEG when ε_(r)=10. FIG.9 shows the electric field distribution of the SEG when ε_(r)=10.

In Table 2, the column for Case I shows that the number of freed chargesis slightly lower, and the efficiency of the SEG drops dramatically.This is due to the loss of the energy stored within the dielectricmaterial.

B. Case II: The Effect of Applied Voltage

In this case, the applied voltage between the conductors is reduced byhalf of the original value (500V) to study the effect on chargeproduction and the efficiency of the SEG, as shown in Table 2 in thecolumn for Case II. FIG. 10 shows the electric potential distribution ofthe SEG. FIG. 11 shows the electric field distribution of the SEG.

Table 2, Case II, shows that the number of freed charges and theefficiency dropped to about half of the values of Case 0. Thus a higherpotential (Case 0) improves both the efficiency of the SEG and thenumber of generated charges. The breakdown voltage and the maximumswitching voltage must be considered in the design.

C. Case III: The Effect of the Diameter of the Thin Wire

In this case, the diameter of the thin wire is doubled to study theeffect on the charge production and the efficiency of the SEG, as shownin Table 2, Case III. FIG. 12 shows the electric potential distributionof the SEG. FIG. 13 shows the electric field distribution of the SEG.

Table 2, Case III, shows that the number of freed charges is slightlyhigher due to the slight decrement of distance between the conductors,while the efficiency of the SEG drops dramatically.

D. Case IV: The Effect of the Thin Metal Sheet Diameter

In this case, the radii of the cylindrical metal sheet and the metallicsphere are doubled to study the effects on charge production and theefficiency of the SEG, see Table 2, Case IV. FIG. 14 shows the electricpotential distribution of the SEG for r₂=1, r₃=2.1. FIG. 15 shows theelectric field distribution of the SEG for r₂=1, r₃=2.1.

Table 2, Case IV, shows that the number of freed charges increases dueto the increase in surface area of the thin metal sheet, while theefficiency of the SEG is slightly decreased.

E. Case V: The Effect of Metal Sheet Thickness

In this case, the thickness of the thin metal sheet is doubled to studythe effects on charges production and the efficiency of the SEG, seeTable 2 Case V. FIG. 16 shows the electric potential distribution of theSEG for doubled thickness. FIG. 17 shows the electric field distributionof the SEG for doubled thickness.

Table 2, Case V, shows that the number of freed charges is slightlylower than for Case 0, because the number of charges on the thin wireare slightly higher while the charges on the metal sheet are slightlylower. This will lead to lower freed charges and lower efficiency. Thegreater the thickness of the cylindrical metal sheet, the greater thenumber of charges which accumulate, which leads to higher energy storedwithin the SEG.

TABLE 2 Parameters and output of the SEG Case 0 Case I Case II Case IIICase IV Case V V₁ (Volt) 500 500 250 500 500 500 V2 (Volt) −500 −500−250 −500 −500 −500 ε_(r) 1 10 1 1 1 1 r₁ (mm) 0.04 0.04 0.04 0.08 0.040.04 r₂ (mm) 1 1 1 1 2 1 r₃ (mm) 1.1 1.1 1.1 1.1 2.1 1.2 Q₁   1.74644e−9  1.73631e−8    8.7322e−10   2.19035e−9    1.3409e−9   1.77257e−9(Coulombs) Q₂ −3.22398e−9 −1.88247e−8 −1.61199e−9  −3.66845e−9 −3.4159e−9 −3.13439e−9 (Coulombs) Q_(free) −1.47754e−9  −1.4616e−9 −7.3877e−10  −1.4781e−9  −2.075e−9 −1.36182e−9 (Coulombs) Energy Stored  1.17827e−6   9.03654e−6   2.94569e−7    1.41549e−6 −1.14532e−6  1.19127e−6 (J) When Q1 = −Q2 Energy Stored   6.25078e−7   8.63198e−6  2.18325e−7    1.0802e−6    6.2438e−7   8.98687e−7 (J) Efficiency46.950% 4.48% 25.88% 23.69% 45.48% 24.56%

From the previous results, the optimum design of the SEG must havehigher metal sheet area for the cylindrical metal sheet, while the areaof the thin metal wire must be as small as possible. In addition, theapplied voltage must be as large as possible, taking into account thebreakdown voltage and the maximum voltage specifications of the switchesor transistors. Furthermore, the thickness of the cylindrical metalsheet must be as small as possible, so fewer charges are retained on thethin metal sheet and lower energy is stored within the SEG.

In summary, a static electrostatic generator (SEG) has been describedwith an efficiency reaching up to 46.95%, especially in the case ofideal switching transistors. The SEG consists of a thin wire and a thinmetallic sheet enclosed by a metal sphere to act as a charge collector.The SEG can generate negative or positive charges by simply reversingthe polarity of the DC voltage source. The freed charges are transferredto the metal surface of the sphere very quickly, yielding a set amountof charge with each switching operation. The amplitude of the DC voltageand the geometric design of the SEG can control the amount of charge onthe surface of the sphere. Thus, if a set amount of charge is requiredto be deposited on the enclosed metal, these charges must be amultiplication of each set generated. Therefore, the SEG gives a certaindegree of control over how much charge can be on the enclosed metalsurface. The efficiency of the SEG is heavily dependent on the appliedvoltage and the geometric design. This SEG is a relatively simpledesign, static, controllable, lightweight, small, and does not requireany mechanical moving parts, which is a big advantage over many otherelectrostatic generators.

The SEG of the present disclosure may be used to power a variety ofelectrical devices. For example, photocopiers, ionizers, paint sprayers,defibrillators and some air fresheners use static electricity.

In a non-limiting example, the SEG of the present disclosure may be usedas an ionizer to clean the air in an enclosure (see (290) in FIG. 1 ).The SEG may charge air molecules in air. These charged air moleculesattract dust or dirt in the air. The charged air molecules and dust ordirt bond together to form dense particles which fall to the bottomsurface of the enclosure, and which can be vacuumed or otherwise removedfrom the bottom surface.

In a further non-limiting example, static electricity from the SEG maybe used to create a spark between the SEG and a conductive element of anelectrical circuit. The spark may act as a timer to initiate anoperation in the electrical circuit.

Next, a hardware description of the controller 350 according toexemplary embodiments is described with reference to FIG. 18 . In FIG.18 , the controller (1850) described is representative of the controller350 of FIG. 3 , in which the controller is a computing device whichincludes a CPU 1800 which performs the processes described above/below.The process data and instructions may be stored in memory 1802. Theseprocesses and instructions may also be stored on a storage medium disk1804 such as a hard drive (HDD) or portable storage medium or may bestored remotely.

Further, the claimed advancements are not limited by the form of thecomputer-readable media on which the instructions of the inventiveprocess are stored. For example, the instructions may be stored on CDs,DVDs, in FLASH memory, RAM, ROM, PROM, EPROM, EEPROM, hard disk or anyother information processing device with which the computing devicecommunicates, such as a server or computer.

Further, the claimed advancements may be provided as a utilityapplication, background daemon, or component of an operating system, orcombination thereof, executing in conjunction with CPU 1800 and anoperating system such as Microsoft Windows 7, UNIT, Solaris, LINUX7,Apple MAC-OS and other systems known to those skilled in the art.

The hardware elements in order to achieve the computing device may berealized by various circuitry elements, known to those skilled in theart. For example, CPU 1800 may be a Xenon or Core processor from Intelof America or an Opteron processor from AMD of America, or may be otherprocessor types that would be recognized by one of ordinary skill in theart. Alternatively, the CPU 1800 may be implemented on an FPGA, ASIC,PLD or using discrete logic circuits, as one of ordinary skill in theart would recognize. Further, CPU 1800 may be implemented as multipleprocessors cooperatively working in parallel to perform the instructionsof the inventive processes described above.

The computing device in FIG. 18 also includes a network controller 1806,such as an Intel Ethernet PRO network interface card from IntelCorporation of America, for interfacing with network 1845. As can beappreciated, the network 1845 can be a public network, such as theInternet, or a private network such as an LAN or WAN network, or anycombination thereof and can also include PSTN or ISDN sub-networks. Thenetwork 1845 can also be wired, such as an Ethernet network, or can bewireless such as a cellular network including EDGE, 3G and 4G wirelesscellular systems. The wireless network can also be WiFi, Bluetooth, orany other wireless form of communication that is known.

The computing device further includes a display controller 1808, such asa NVIDIA GeForce GT21 or Quadro graphics adaptor from NVIDIA Corporationof America for interfacing with display 1810, such as a Hewlett PackardHPL2445w LCD monitor. A general purpose I/O interface 1812 interfaceswith a keyboard and/or mouse 1814 as well as a touch screen panel 1816on or separate from display 1810. General purpose I/O interface alsoconnects to a variety of peripherals 1818 including printers andscanners, such as an OfficeJet or DeskJet from Hewlett Packard. A soundcontroller 1820 is also provided in the computing device such as SoundBlaster X-Fi Titanium from Creative, to interface withspeakers/microphone 1822 thereby providing sounds and/or music.

The general purpose storage controller 1824 connects the storage mediumdisk 1804 with communication bus 1826, which may be an ISA, EISA, VESA,PCI, or similar, for interconnecting all of the components of thecomputing device. A description of the general features andfunctionality of the display 1810, keyboard and/or mouse 1814, as wellas the display controller 1808, storage controller 1824, networkcontroller 1806, sound controller 1820, and general purpose I/Ointerface 1812 is omitted herein for brevity as these features areknown.

The exemplary circuit elements described in the context of the presentdisclosure may be replaced with other elements and structureddifferently than the examples provided herein. Moreover, circuitryconfigured to perform features described herein may be implemented inmultiple circuit units (e.g., chips), or the features may be combined incircuitry on a single chipset, as shown on FIG. 19 .

FIG. 19 shows a schematic diagram of a data processing system, accordingto certain embodiments, for performing the functions of the exemplaryembodiments. The data processing system is an example of a computer inwhich code or instructions implementing the processes of theillustrative embodiments may be located.

In FIG. 19 , data processing system 1900 employs a hub architectureincluding a north bridge and memory controller hub (NB/MCH) 1925 and asouth bridge and input/output (I/O) controller hub (SB/ICH) 1920. Thecentral processing unit (CPU) 1930 is connected to NB/MCH 1925. TheNB/MCH 1925 also connects to the memory 1945 via a memory bus, andconnects to the graphics processor 1950 via an accelerated graphics port(AGP). The NB/MCH 1925 also connects to the SB/ICH 1920 via an internalbus (e.g., a unified media interface or a direct media interface). TheCPU Processing unit 1930 may contain one or more processors and even maybe implemented using one or more heterogeneous processor systems.

For example, FIG. 20 shows one implementation of CPU 1930. In oneimplementation, the instruction register 2038 retrieves instructionsfrom the fast memory 2040. At least part of these instructions arefetched from the instruction register 2038 by the control logic 2036 andinterpreted according to the instruction set architecture of the CPU830. Part of the instructions can also be directed to the register 2032.In one implementation the instructions are decoded according to ahardwired method, and in another implementation the instructions aredecoded according a microprogram that translates instructions into setsof CPU configuration signals that are applied sequentially over multipleclock pulses. After fetching and decoding the instructions, theinstructions are executed using the arithmetic logic unit (ALU) 2034that loads values from the register 2032 and performs logical andmathematical operations on the loaded values according to theinstructions. The results from these operations can be feedback into theregister and/or stored in the fast memory 2040. According to certainimplementations, the instruction set architecture of the CPU 1930 canuse a reduced instruction set architecture, a complex instruction setarchitecture, a vector processor architecture, a very large instructionword architecture. Furthermore, the CPU 1930 can be based on the VonNeuman model or the Harvard model. The CPU 1930 can be a digital signalprocessor, an FPGA, an ASIC, a PLA, a PLD, or a CPLD. Further, the CPU830 can be an x86 processor by Intel or by AMD; an ARM processor, aPower architecture processor by, e.g., IBM; a SPARC architectureprocessor by Sun Microsystems or by Oracle; or other known CPUarchitecture.

Referring again to FIG. 19 , the data processing system 1900 can includethat the SB/ICH 1920 is coupled through a system bus to an I/O Bus, aread only memory (ROM) 1956, universal serial bus (USB) port 1964, aflash binary input/output system (BIOS) 1968, and a graphics controller1958. PCI/PCIe devices can also be coupled to SB/ICH 1920 through a PCIbus 1962.

The PCI devices may include, for example, Ethernet adapters, add-incards, and PC cards for notebook computers. The Hard disk drive 1960 andCD-ROM 1966 can use, for example, an integrated drive electronics (IDE)or serial advanced technology attachment (SATA) interface. In oneimplementation the I/O bus can include a super I/O (SIO) device.

Further, the hard disk drive (HDD) 1960 and optical drive 1966 can alsobe coupled to the SB/ICH 1920 through a system bus. In oneimplementation, a keyboard 1970, a mouse 1972, a parallel port 1978, anda serial port 1976 can be connected to the system bus through the I/Obus. Other peripherals and devices that can be connected to the SB/ICH1920 using a mass storage controller such as SATA or PATA, an Ethernetport, an ISA bus, a LPC bridge, SMBus, a DMA controller, and an AudioCodec.

Moreover, the present disclosure is not limited to the specific circuitelements described herein, nor is the present disclosure limited to thespecific sizing and classification of these elements. For example, theskilled artisan will appreciate that the circuitry described herein maybe adapted based on changes on battery sizing and chemistry, or based onthe requirements of the intended back-up load to be powered.

Additionally, some implementations may be performed on modules orhardware not identical to those described. Accordingly, otherimplementations are within the scope that may be claimed.

The above-described hardware description is a non-limiting example ofcorresponding structure for performing the functionality describedherein.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

The invention claimed is:
 1. An air ionizer for air purification, comprising: an enclosure containing a static electrostatic generator; wherein the static electrostatic generator comprises: a conductive metal wire made of copper having a first and a second end; a cylindrical conductive metal sheet made of aluminum coaxial with the conductive metal wire, the cylindrical conductive metal sheet having a first end and a second end, an interior surface and an exterior surface; a conductive metal sphere made of aluminum surrounding the conductive metal wire and the cylindrical conductive metal sheet, the conductive metal sphere having an interior surface and an exterior surface, wherein the interior surface of the conductive metal sphere is evenly spaced from the exterior surface of the cylindrical conductive metal sheet; a first switch, a second switch and a third switch, each switch having a first side and a second side; a battery having a first electrode and a second electrode, wherein the first electrode is connected to the first end of the conductive metal wire and the second electrode is attached to the first side of the first switch; wherein the second side of the first switch is connected to the first end of the cylindrical conductive metal sheet; the second switch having its first end connected to the second end of the conductive metal wire and its second end connected to the second end of the cylindrical conductive metal sheet; the third switch having its first end connected to the cylindrical conductive metal sheet and its second end connected to the interior surface of the conductive metal sphere; a controller connected to each of the switches and having timing circuitry configured to operate the switches at specified times in order to generate static electrostatic charges on the surface of the conductive metal sphere; and a dielectric material between the conductive metal wire and the cylindrical conductive metal sheet.
 2. The air ionizer of claim 1, wherein the dielectric material has relative permittivity, ε_(r), in the range of 1-10, and is selected from the group consisting of air, PTFE, polyethylene, polymide, polypropylene, polystyrene, aluminum oxide, ceramic, mica and glass.
 3. The air ionizer of claim 1, wherein the thin metal wire has a radius in the range of 0.001 to 2.0 mm.
 4. The air ionizer of claim 1, wherein the switches are selected from the group consisting of transistors, electrically actuated switches, and electrically actuated mechanical switches.
 5. The air ionizer of claim 4, wherein the transistors are selected from the group consisting of MOSFETS, JFETS, FETs, and bi-polar junction transistors (BJT).
 6. The air ionizer of claim 1, wherein the controller further comprises a timing module connected to the switches and a microprocessor connected to the timing module, the microprocessor having circuitry configured to control the timing module to turn the switches ON or OFF.
 7. The air ionizer of claim 1, wherein the battery comprises a battery bank having a plurality of internal, switchable batteries; wherein the controller has circuitry configured to adjust the voltage applied to the battery by switching the internal batteries of the battery bank. 